Study Shows Novel sa-mRNA Vaccines Offer Robust, Broad, Enduring Protection Against COVID-19 Variants
Late-breaking data presented at 9th
Messenger RNA (mRNA) vaccine technology protects against infectious diseases by instructing cells in the body to make a specific protein, stimulating the immune response, and leaving a blueprint to recognize and fight future infection. However, sa-mRNA also provides the body with instruction to make copies of the mRNA, amplifying the amount of protein made. This advanced technology has shown the potential to offer longer duration of immune response at considerably lower doses compared to conventional mRNA vaccines.
“Current mRNA technologies provide effective initial immunogenicity against COVID-19, but the results of this study show that our sa-mRNA vaccine platform can offer improvements in duration and breadth of protection against new and emerging variants,” said Igor Smolenov, Chief Development Officer, Arcturus. “We are proud of the role Arcturus has played, collaborating with CSL, in advancing sa-mRNA vaccine development.”
CSL’s vaccine business, CSL Seqirus, is Arcturus’ global exclusive partner for the development of novel mRNA vaccines against SARS-CoV-2 (COVID-19), influenza and pandemic preparedness. CSL has a dynamic portfolio of lifesaving medicines, including those that treat hemophilia, hereditary angioedema (HAE) and immune deficiencies, vaccines to prevent influenza, and therapies in iron deficiency and nephrology.
“We are encouraged by the findings of the study, indicating the sa-mRNA platform’s potential to solve the challenge of mRNA vaccine waning immunity over time, and thereby provide prolonged protection at lower doses,” said
Study Design and Results
For this phase 1/2 randomized, observer-blind study conducted in the US and
All three vaccines induced robust neutralizing immune response against the D614G variant at Day 29 with geometric mean fold rises (GMFR) from pre-booster levels of 20.0, 36.7 and 23.5 after ARCT-021, ARCT-154, and ARCT-165, respectively. ARCT-154, a leading candidate, induced a broad, cross-neutralizing immune response, which persisted up to one-year post-booster with no further boosting. Similar trends were observed for other SARS-CoV-2 variants including Beta, Delta, Omicron BA.1, Omicron BA.2, and Omicron BA.4/5. Additional exploratory testing confirmed cross-neutralization against emergent BQ.1.1 and XBB.1.5 Omicron sub-lineages with GMFRs of 12.8 and 3.4, respectively, at Day 29 post-booster. Adverse events were mild or moderate and resolved quickly, and rates of related or severe AEs were low.
Founded in 2013 and based in
Forward Looking Statement
This press release contains forward-looking statements that involve substantial risks and uncertainties for purposes of the safe harbor provided by the Private Securities Litigation Reform Act of 1995. Any statements, other than statements of historical fact included in this press release, are forward-looking statements, including those regarding strategy, future operations, the likelihood of success of the Company’s pipeline and partnered programs (including the COVID-19 program partnered with CSL Seqirus), the likelihood that ARCT-154 or any other Arcturus vaccine candidate will be successful or continue to advance, the likelihood that the Phase 1/2 clinical data will be predictive of, or consistent with, future clinical results, the likelihood that the Company’s sa-mRNA vaccine platform will offer improvements in duration and breadth of protection, and the impact of general business and economic conditions. Arcturus may not actually achieve the plans, carry out the intentions or meet the expectations or projections disclosed in any forward-looking statements such as the foregoing and you should not place undue reliance on such forward-looking statements. These statements are only current predictions or expectations, and are subject to known and unknown risks, uncertainties, and other factors that may cause our or our industry’s actual results, levels of activity, performance or achievements to be materially different from those anticipated by the forward-looking statements, including those discussed under the heading "Risk Factors" in Arcturus’ most recent Annual Report on Form 10-K, and in subsequent filings with, or submissions to, the
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